%0 Journal Article %T Tetracycline and Glutathione Inhibit Matrix Metalloproteinase Activity: An In Vitro Study Using Culture Supernatants of L929 and Dalton Lymphoma Cell Lines %A Gajanan Kendre %A Rahul Raghavan %A Sanith Cheriyamundath %A Joseph Madassery %J Journal of Cancer Research %D 2013 %R 10.1155/2013/328134 %X Tetracycline and glutathione inhibited the protease activities of matrix metalloproteinase-2 and matrix metalloproteinase-9 expressed by mouse fibrosarcoma cells (L929) and Dalton lymphoma cells, respectively. The inhibitory activity of the tetracycline may be due to its ability to chelate metal ions such as calcium and zinc. Gelatin-zymography technique was used to demonstrate the inhibitory activity of both tetracycline and glutathione. The intensity of the bands corresponding to metalloproteinase activity in zymography gel was reduced in the presence of 50¨C100£¿¦Ìg/mL of tetracycline. The presence of 10¨C100£¿¦Ìg/mL of tetracycline in the medium increased the adherence of L929 cancer cells. These results clearly indicate the antimetastatic property of tetracycline. Reduced glutathione, a compound which is produced endogenously by the cells to maintain the redox status, was shown to inhibit the matrix metalloproteinase activity (in vitro). Therefore, it is assumed that decreased glutathione levels in synovial fluids or plasma might increase the activity of MMP. Reduced glutathione at 100£¿¦Ìg/mL inhibited the metalloproteinase activity in gelatin-zymographic gel. As both tetracycline and glutathione exhibited an inhibitory effect on matrix metalloproteinase activity, it was of great interest to check their clinical effects on various MMP associated pathological conditions such as cancer metastasis and arthritis. Here we report that tetracycline and reduced glutathione inhibited the activity of MMP2 completely and activity of MMP9 partly. 1. Introduction Matrix metalloproteinases are zinc dependent neutral endopeptidases and they were originally described as collagenolytic factor that is required for the dissolution of tadpole tail [1]. The primary function of MMP is to remodel the extracellular matrix. MMPs are involved in fetal tissue development, tissue repair, and wound healing [2]. MMPs are secreted into the extracellular matrix as zymogen called proMMP and cleavage of propeptide from the proMMP makes it catalytically active [3]. MMP2 and MMP9 are the two gelatinases that can degrade the collagenase IV basement membrane and the overproduction of MMP2 and MMP9 during pathological conditions like cancers is responsible for the cancer cell penetration through extracellular matrix. MMP2 and MMP9 have been associated with the progression of various cancers like breast cancer, colorectal cancer, nonsmall cell lung cancer, and gastric and pancreatic cancer [2]. Previous reports from clinical and knockout mice studies shows that higher expression of %U http://www.hindawi.com/journals/jcr/2013/328134/